Double-storey extensions across Doncaster
If you live in Doncaster and want more space without moving, a double-storey extension is one of the most practical ways to get it. We handle the drawings, approvals and the build.
- Guide price in DoncasterFrom £35,500 inc VAT
- PlanningUsually a householder application
- Build time16–24 weeks on site
- Postcode districtsDN1, DN2, DN3, DN4, DN5
How much does a double-storey extension cost in Doncaster?
Labour and material costs vary across the UK, so for Doncaster we use our Yorkshire and the Humber factor (×0.94). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Doncaster: £1,460 to £2,820 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m, two floors 24 m² | £35,500 – £43,000 | £40,500 – £53,500 | £51,500 – £68,000 |
| 4 m × 4 m, two floors 32 m² | £46,500 – £56,000 | £54,000 – £71,000 | £69,000 – £90,500 |
| 4 m × 6 m, two floors 48 m² | £69,500 – £83,500 | £81,000 – £106,500 | £103,500 – £135,500 |
For a figure based on your own dimensions, use our guide-price tool.
What we take care of
- Householder planning application where needed
- Ground and first floor structure, roof tied into the existing roof
- Insulation, plastering, electrics and plumbing to finish
- Measured survey, design and planning drawings
- Breaking through at both levels, stairs and landing changes where needed
- Building regulations drawings and structural design
The roof is what makes a two-storey extension look right or wrong. We match the pitch and materials of the main house wherever possible and plan the upstairs layout around the existing landing so the new rooms feel original rather than bolted on.
Extensions in and around Doncaster
Postcode districts we cover around Doncaster include DN1, DN2, DN3, DN4, DN5, DN12. We also work in nearby Adwick le Street (4 miles), Rawmarsh (10 miles), Dinnington (11 miles), Rotherham (11 miles).
For homes towards West Yorkshire, South Elmsall is around 8 miles away. Homes across Yorkshire and the Humber range from back-to-back and through terraces to large suburban semis, and extension options vary with them.
Planning and approvals in Doncaster
In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
The planning position for a specific Doncaster address depends on its history and any designations, which is why we check it at the first visit.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Applications are decided by the local planning authority (your district, borough or unitary council).
How the project works
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Double-storey extension questions answered
Do I need building regulations approval in Doncaster?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Doncaster, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
How long does a double-storey extension take to build in Doncaster?
On site, typically 16 to 24 weeks once approvals are in place. Before that, allow 8–16 weeks design and approvals.
Is a two-storey extension cheaper per square metre?
Usually. Our guide range is about £1,460 to £2,820 per m² of new floor area including VAT, compared with £1,640 to £3,200 per m² for single-storey work, because the foundations and roof are shared across two floors.
Does a double-storey extension need planning permission?
Often, yes. In England a two-storey rear extension can be permitted development only if it projects no more than 3 m and sits at least 7 m from the rear boundary, with matching roof pitch and obscure side windows. Side extensions over one storey always need planning permission. We confirm the route at the survey.
Book a free site visit in Doncaster
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.